Method and apparatus for adaptive peer to peer communication selection in wireless communication system

ABSTRACT

A method for operating a Base Station (BS) in a wireless communication system capable of supporting a Peer-to-Peer (P2P) communication is provided. The method includes receiving at least one response message from at least one Mobile Station (MS) that has received a request message from a first MS and determining whether to allow the first MS to performs the P2P communication with a second MS based on the at least one response message.

PRIORITY

This application is a continuation application of a prior applicationSer. No. 12/169,404, filed on Jul. 8, 2008, which claimed the benefitunder 35 U.S.C. §119(a) of a Korean patent application filed on Jul. 9,2007 in the Korean Intellectual Property Office and assigned SerialNumber 10-2007-0068843, the entire disclosures of each of which ishereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and apparatus for establishinga Peer-to-Peer (P2P) connection in a wireless communication system. Moreparticularly, the present invention relates to a method and apparatusfor adaptive P2P communication selection in consideration of a wirelessenvironment between Mobile Stations (MSs).

2. Description of the Related Art

In a wireless communication system, whenever first and second MobileStations (MSs) desire to communicate with each other, the first ortransmitting MS must make a call to the second or receiving MS through awireless communication network regardless of the distance between thetransmitting and receiving MSs. That is, a connection with the receivingMS is established via a Base Station (BS), a mobile switching center, orthe like, constituting the wireless communication system, regardless ofthe distance between the transmitting MS and the receiving MS. However,if the distance between the transmitting MS and the receiving MS is veryclose, direct communication can be more reasonable. Directcommunication, that is, communication that is not established via theBS, is referred to as Peer-to-Peer (P2P) communication. Various servicescan be provided through the P2P communication, such as, transmission ofa massive file, Voice over Internet Protocol (VoIP), video conference,etc. Also, the P2P communication can provide the same service quality asthat conventionally provided via the BS.

The MSs conventionally use a different frequency band for general P2Pcommunication than a frequency band allocated to the wirelesscommunication system. To process the additional frequency band, aseparate Radio Frequency (RF) transmitting/receiving apparatus is used.For example, Infrared Data Association (IrDA) communication, Bluetoothcommunication, etc., are used in the P2P communication. Alternatively,when the P2P communication and the wireless communication use the samefrequency band, bandwidth efficiency can be improved by flexiblyadjusting each transmission band through effective resource managementso long as interference is prevented. One project that is researchingsuch P2P communication is the Wireless world Initiative NEw Radio(WINNER) system in Europe.

FIG. 1 illustrates an example of a P2P communication environment in awireless communication system.

Referring to FIG. 1, a plurality of MSs 102, 104 and 106 are located ina service coverage area of a BS 100, and the MS_y 108 is located in aservice coverage area of another BS 110. The MSs 102 to 108 cancommunicate with receiving MSs via the corresponding BSs 100 and 110.Although an additional P2P communication module is not included,wireless resources of the mobile communication system can be reused toperform P2P communication between the MSs.

In the wireless communication system of FIG. 1, when the MS_1 102desires to communicate with the MS_2 104, the MS_1 102 determineswhether the connection will be established in a P2P communication modeor a wireless communication mode. For example, when the MS_1 102 detectsthat the receiving MS (i.e., the MS_2 104) is located close to the MS_1102, the MS_1 102 can request the BS 100 to establish a P2P connectionwith the MS_2 104. Alternatively, the MS_1 102 may attempt direct P2Pcommunication with the MS_2 104 not via the BS 100. In addition,although the MS_1 102 does not detect the location of the receiving MS(i.e., the MS_2 104), the MS_1 102 can perform P2P communication bygathering information of the MS_2 104. However, if the MS_1 102 islocated in the service coverage area of the BS 100 and desires P2Pcommunication with the MS_y 108 whose location is not detected, the MS_1102 cannot perform P2P communication with the MS_y 108 because the MS_1102 cannot gather information of the MS_y 108 due to a distance betweenthe MS_1 102 and the MS_y 108. In such a case, in order to communicatewith the MS_y 108 (or the MS_x 106), it is preferable that the MS_1 102establishes a BS-assisted connection instead of establishing the P2Pconnection.

To perform communication, the MS_1 102 must select either the P2Pcommunication mode or the wireless communication mode by considering awireless environment and a distance from the receiving MS, which isdifficult in practice. Even if the selection of a communication mode isachieved by the MS_1 102 in consideration of the wireless environmentand the distance from the receiving MS, there is no guarantee that theselected communication mode is effective in terms of resourceutilization.

As described above, when an MS attempts a call connection with anotherMS in a wireless communication system, there is no method of adaptivelyselecting a communication mode between BS-assisted communication (i.e.,wireless communication) and P2P communication among MSs by consideringeffective utilization of overall resources from the viewpoint of a BS.

SUMMARY OF THE INVENTION

An aspect of the present invention is to address at least theabove-mentioned problems and/or disadvantages and to provide at leastthe advantages described below. Accordingly, an aspect of the presentinvention is to provide a method and apparatus for establishing aPeer-to-Peer (P2P) connection in a wireless communication system.

In accordance with an aspect of the present invention, a method ofoperating a Base Station (BS) for establishing a communication modebetween Mobile Stations (MSs) in a wireless communication system isprovided. The method includes, upon receiving a connection requestmessage from a transmitting MS, broadcasting an instruction message toone or more neighbor MSs, receiving P2P-related information from areceiving MS among the neighbor MSs, selecting a communication mode bydetermining whether P2P communication is possible between MSs accordingto the P2P-related information and, if P2P communication is possiblebetween the MSs, transmitting a connection response message to thetransmitting MS and the receiving MS.

In accordance with another aspect of the present invention, a method ofoperating a transmitting MS for establishing a communication modebetween MSs in a wireless communication system is provided. The methodincludes, after requesting a connection to a BS, broadcasting a P2Preport request message for checking possibility of P2P communicationwith a receiving MS, after broadcasting the P2P report request message,receiving a connection response message that informs the possibility ofP2P communication with the receiving MS and establishing a connectionwith the receiving MS in a desired communication mode according to theconnection response message.

In accordance with another aspect of the present invention, a method ofoperating a receiving MS for establishing a communication mode betweenMSs in a wireless communication system is provided. The method includes,after receiving a P2P setup ready message for instructing preparation ofP2P setup from a BS, preparing P2P setup, after preparing the P2P setup,receiving a P2P report request message for checking possibility of P2Pcommunication from a transmitting MS and reporting P2P-relatedinformation to the BS.

In accordance with another aspect of the present invention, a BSapparatus for establishing a communication mode between MSs in awireless communication system is provided. The apparatus includes acontroller for broadcasting an instruction message to one or moreneighbor MSs upon receiving a connection request message from atransmitting MS, for receiving P2P-related information from a receivingMS among the neighbor MSs, and, if P2P communication is possible betweenthe MSs, for transmitting a connection response message to thetransmitting MS and the receiving MS and a mode selector for selecting acommunication mode by determining whether P2P communication is possiblebetween MSs according to the P2P-related information.

In accordance with another aspect of the present invention, atransmitting MS apparatus for establishing a communication mode betweenMSs in a wireless communication system is provided. The apparatusincludes a controller for broadcasting a P2P report request message forchecking possibility of P2P communication with a receiving MS afterrequesting a connection to a BS, for receiving a connection responsemessage that informs the possibility of P2P communication with thereceiving MS after broadcasting the P2P report request message, and forestablishing a connection with the receiving MS in a desiredcommunication mode according to the connection response message.

In accordance with another aspect of the present invention, a receivingMS apparatus for establishing a communication mode between MSs in awireless communication system is provided. The apparatus includes acontroller for preparing P2P setup after receiving a P2P setup readymessage for instructing preparation of P2P setup from a BS, forreceiving a P2P report request message for checking possibility of P2Pcommunication from a transmitting MS after preparing the P2P setup, andfor reporting P2P-related information to the BS.

Other aspects, advantages, and salient features of the invention willbecome apparent to those skilled in the art from the following detaileddescription, which, taken in conjunction with the annexed drawings,discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of certainexemplary embodiments of the present invention will be more apparentfrom the following description taken in conjunction with theaccompanying drawings in which:

FIG. 1 illustrates an example of a Peer-to-Peer (P2P) communicationenvironment in a wireless communication system;

FIG. 2 is a flow diagram illustrating signal flows when a Base Station(BS) selects a communication mode by considering a wireless environmentbetween MSs in a wireless communication system according to an exemplaryembodiment of the present invention;

FIG. 3 is a flowchart illustrating an operation of a BS for adaptivelyselecting a communication mode in a wireless communication systemaccording to an exemplary embodiment of the present invention;

FIG. 4 is a flowchart illustrating an operation of a Mobile Station (MS)for adaptively selecting a communication mode in a wirelesscommunication system according to an exemplary embodiment of the presentinvention;

FIG. 5 is a block diagram illustrating an MS for establishing a P2Pconnection between MSs in a wireless communication system according toan exemplary embodiment of the present invention; and

FIG. 6 is a block diagram illustrating a BS for establishing a P2Pconnection between MSs in a wireless communication system according toan exemplary embodiment of the present invention.

Throughout the drawings, it should be noted that like reference numbersare used to depict the same or similar elements, features andstructures.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following description with reference to the accompanying drawings isprovided to assist in a comprehensive understanding of exemplaryembodiments of the invention as defined by the claims and theirequivalents. It includes various specific details to assist in thatunderstanding but these are to be regarded as merely exemplary.Accordingly, those of ordinary skill in the art will recognize thatvarious changes and modifications of the embodiments described hereincan be made without departing from the scope and spirit of theinvention. Also, descriptions of well-known functions and constructionswill be omitted for clarity and conciseness.

Hereinafter, an exemplary method and apparatus for adaptively selectinga communication mode by a Base Station (BS) in consideration of awireless environment between Mobile Stations (MSs) in a wirelesscommunication system will be described. The communication mode includesa Peer-to-Peer (P2P) communication mode and a wireless communicationmode. The P2P communication mode is defined as a mode in which two MSscommunicate with each other not via the BS. The wireless communicationmode is defined as a mode in which communication is achieved via the BS.

In a P2P communication environment shown in FIG. 1, an MS_1 102 desirescommunication with a receiving MS which may be located within a servicecoverage area A of a BS 100 or may be located within a cell or servicecoverage area B of BS 110. In such a situation, if the MS_1 102 desirescommunication with an MS_2 104, direct communication between the MSs(i.e., P2P communication) is advantageous over wireless communicationvia the BS in terms of channel conditions and resource utilization. SomeMSs (e.g., an MS_x 106 and an MS_y 108) are located in a region where asignal transmitted from the MS_1 102 cannot be delivered. In this case,since P2P communication cannot be achieved, communication using the BSis more effective. An exemplary process of adaptively establishing a P2Pconnection will be described below with reference to FIG. 2.

FIG. 2 is a flow diagram illustrating signal flows when a BS selects acommunication mode by considering a wireless environment between MSs ina wireless communication system according to an exemplary embodiment ofthe present invention.

Referring to FIG. 2, an MS 102 transmits a connection request(hereinafter, connection_req) message to a BS 100 in step 210. Theconnection_req message transmitted by MS 102 indicates a desire by theMS 102 to communicate with an MS 104. That is, in the illustratedexample of FIG. 2, the MS 102 is a transmitting MS which desires generalcommunication. Since the MS 102 does not know a location of thereceiving MS 104 or a current wireless channel condition, the MS 102requests the BS 100 to establish a general call connection according toa preset communication link.

In step 212, in order to determine the possibility of P2P communicationbefore establishing a connection in the wireless communication mode, theBS 100 broadcasts a P2P setup preparation (hereinafter, P2P_setup_ready)message to MSs 104, 106, and 108. In this case, the MSs 104 and 106,located in a service coverage area of the BS 100, receive theP2P_setup_ready message, and prepare to receive a P2P Neighbor Reportrequest (hereinafter, PNR_req) message from their neighbor MSs. However,the MS 108 is located too far from the BS 100 and thus cannot receivethe P2P_setup_ready message.

The MSs 104 and 106, which have received the P2P_setup_ready message andare located within the service coverage area of the BS 100, may be in astate of a sleep mode in which no communication is currently made withthe BS 100 or in a state in which the MS is currently communicating withanother MS. In the former case, the sleep mode is shifted to a P2Pactive mode, and power consumed in the MSs can be effectively reduced.In the latter case, by receiving the P2P setup_ready_message, wirelesscommunication and P2P communication can be simultaneously performed.

After a time period has elapsed, the MS 102 broadcasts the PNR_reqmessage in step 214 so that the MS 104 will transmit P2P-relatedinformation to the BS 100. The time period is begun in step 210 when theMS 102 transmits the Connection_req message and has a durationsufficient to allow the receiving MSs to receive the P2P_setup_readymessage and prepare for receipt of the PNR_req message.

In step 216, the BS 100 receives a message in response to the PNR_reqmessage (hereinafter, the response message will be referred to as aPNR_rsp message) from the MS 104 among the MSs 104 and 106 which havereceived the PNR_req message. The PNR_rsp message includes a variety ofinformation such as a P2P group IDentifier (ID) (hereinafter,P2P_GroupID), a transmitting MS ID (hereinafter, Sender_ID), channelpower information (hereinafter, Channel_Power_info), a call status(hereinafter, Call_status), etc. According to an exemplary embodiment,as shown in step 218, the BS 100 may receive the PNR_rsp message notonly from the corresponding MSs but also from all or some of MSs whichhave received the PNR_req message.

In step 220, the BS 100 determines whether P2P communication will beused between the MS 102 and the MS 104 according to information includedin the PNR_rsp message received from MS 104. In other words, the BS 100determines whether the MS 102 and the MS 104 are in an environment whereP2P communication can be achieved and is favorable. In an exemplaryimplementation, the BS 100 creates a list or table of neighbor MSs thathave responded to the PNR_req message, listing the MSs by connection ID,including their associated P2P information obtained in the PNR_rspmessages. The table may include results regarding P2P communicationincluding which of the MSs may communicate by P2P with other MSs.

In step 222, the BS 100 selects a desired communication mode. Forexample, if a distance between the MSs is close enough to perform P2Pcommunication and the MSs are located far from the BS 100 so that aBS-MS channel condition is poor, then P2P communication is advantageousover wireless communication. In this case, the BS 100 selects the P2Pcommunication mode for the purpose of effective utilization ofresources. On the contrary, if the distance between the MSs is far, andthe MSs are located close to the BS 100 so that the BS-MS channelcondition is good, then the BS 100 selects the wireless communicationmode. For example, referring back to FIG. 1, the P2P communication modeis selected for communication between the MS 102 and the MS 104, and thewireless communication mode is selected for communication between the MS102 and the MS 106 or between the MS 102 and the MS 108.

According to another exemplary embodiment, the MS 102 rather than the BS100 may receive the PNR_rsp message from the MS 104, determine thepossibility of P2P communication between the MS 102 and the MS 104, andreport the determination result to the BS 100.

In step 224, the BS 100 transmits a connection response (hereinafter,Connection_rsp) message to the MS 102 and the MS 104.

In step 226, the MS 102 and the MS 104 communicate with each otheraccording to the communication mode selected by the BS 100. For example,as illustrated in FIG. 2, when the P2P communication mode is selected, aP2P connection is established according to a preset P2P communicationprocess, and when the wireless communication mode is selected, aconnection is established according to a call connection process via theBS 100.

Thereafter, the procedure of FIG. 2 ends.

FIG. 3 is a flowchart illustrating an operation of a BS for adaptivelyselecting a communication mode in a wireless communication systemaccording to an exemplary embodiment of the present invention.

Referring to FIG. 3, the BS receives a connection_req message from an MSin step 300.

In step 302, in order to determine the possibility of P2P communicationbefore establishing a connection in the wireless communication mode, theBS broadcasts a P2P_setup_ready message to relevant MSs.

In step 304, the BS receives P2P-related information (e.g., aP2P_GroupID, a Sender_ID, a Channel_Power_info, a Call_status, etc.)from the relevant MSs.

In step 306, the BS creates a list of neighbor MSs by using theP2P-related information received from the relevant MSs.

In step 308, according to the neighbor-MS information, the BS determineswhether P2P communication is possible between the MSs. In other words,by determining whether the MSs are in a P2P communicable environment,the BS selects a desired communication mode.

In step 310, the BS transmits a connection_rsp message to the relevantMSs.

Thereafter, the procedure of FIG. 3 ends.

FIG. 4 is a flowchart illustrating an operation of an MS for adaptivelyselecting a communication mode in a wireless communication systemaccording to an exemplary embodiment of the present invention.

Referring to FIG. 4, the MS transmits a connection_req message to a BSincluding a request to communicate with another MS in step 400.

In step 402, after a time period elapses, the MS broadcasts a messagefor requesting P2P-related information to neighbor MSs.

In step 404, the MS receives a connection_rsp message from the BS.

In step 406, the MS determines a communication mode. If thecommunication mode is the P2P communication mode, the MS establishes aP2P connection with a corresponding MS in step 408.

Otherwise, if the communication mode is not the P2P communication mode,the MS communicates with the corresponding MS via the BS in step 410.

Thereafter, the procedure of FIG. 4 ends.

FIG. 5 is a block diagram illustrating an MS for establishing a P2Pconnection between MSs in a wireless communication system according toan exemplary embodiment of the present invention.

Referring to FIG. 5, the MS includes a Radio Frequency (RF) processor500 for reception, an Orthogonal Frequency Division Multiplexing (OFDM)demodulator 502, a message processor 504, a first controller 506, amessage generator 508, an OFDM modulator 510, an RF processor 512 fortransmission, and a P2P controller 514.

The RF processor 500 converts an RF signal received through an antennainto a baseband analog signal. The OFDM demodulator 502 converts theanalog signal received from the RF processor 500 into sample data.Further, the OFDM demodulator 502 converts the sample data intofrequency-domain data through Fast Fourier Transform (FFT), and selectsdata of subcarriers to be received in practice from the frequency-domaindata. Furthermore, the OFDM demodulator 502 demodulates and decodes dataaccording to a preset Modulation and Coding Scheme (MCS) level andoutputs the data to the message processor 504.

The message processor 504 decomposes a control message received from theOFDM demodulator 502 and provides the decomposition result to the firstcontroller 506. Further, in a state of being switched to a P2Pcommunication mode, the message processor 504 decomposes a P2P controlmessage received from the OFDM demodulator 502 and provides thedecomposition result to the P2P controller 514. For example, the messageprocessor 504 processes a P2P connection message.

The first controller 506 performs a process suitable for informationreceived from the message processor 504 and provides the result to themessage generator 508. Further, in a state of being switched to the P2Pcommunication mode, the P2P controller 514 performs a process suitablefor P2P communication control information received from the messageprocessor 504 and provides the result to the message generator 508.

The message generator 508 generates a message by using a variety ofinformation received from the first controller 506 or the P2P controller514 and outputs the generated message to the OFDM modulator 510 of aphysical layer. For example, the message generator 508 generates amessage for requesting information on neighbor MSs.

The OFDM modulator 510 codes and modulates data received from themessage generator 508 according to the preset MCS level. Further, theOFDM modulator 510 converts the modulated data into sample data (i.e.,an OFDM symbol) through Inverse Fast Fourier Transform (IFFT).Furthermore, the OFDM modulator 510 converts the sample data into ananalog signal and outputs the analog signal to the RF processor 512. TheRF processor 512 converts the analog signal into an RF signal andtransmits the RF signal through an antenna.

The first controller 506 may receive information, which is required whena general wireless communication protocol is processed through a mobileswitching station or a BS, from an element of the physical layer or maygenerate a control signal to be delivered to the element of the physicallayer. The first controller 506 can control and use a transmitter and areceiver in a Time Division Duplex (TDD) or Frequency Division Duplex(FDD) mode.

The P2P controller 514 may receive information, which is required when aP2P communication protocol is processed between MSs, from an element ofthe physical layer or may generate a control signal to be delivered tothe element of the physical layer. The P2P controller 514 can also beused based on the TDD or FDD mode. In addition thereto, the P2Pcontroller 514 broadcasts a PNR_req message, and, if the BS selects theP2P communication mode, controls a P2P connection according to a presetP2P communication process.

In the aforementioned structure, the first controller 506 is provided asa protocol controller and controls the message processor 504, themessage generator 508, and the P2P controller 514. That is, the firstcontroller 506 can function as the message processor 504, the messagegenerator 508, and the P2P controller 514. Although these elements areseparately configured in the illustrated example, this is forexplanation purposes only. Thus, in practice, all or some of theseelements may be controlled by the first controller 506.

FIG. 6 is a block diagram illustrating a BS for establishing a P2Pconnection between MSs in a wireless communication system according toan exemplary embodiment of the present invention.

Referring to FIG. 6, the BS includes an RF processor 600 for reception,an OFDM demodulator 602, a message processor 604, a controller 606, amessage generator 608, an OFDM modulator 610, an RF processor 612 fortransmission, a mode selector 614, a P2P information manager 616, and aP2P setup unit 618.

The RF processor 600, the OFDM demodulator 602, the message processor604, the controller 606, the message generator 608, the OFDM modulator610, and the RF processor 612 have substantially the same functions asdescribed with reference to FIG. 5, and thus detailed descriptionsthereof will be omitted for brevity.

In a P2P connection process, the P2P information manager 616 allocatesresources so that P2P communication can be maintained between thetransmitting MS and a receiving MS, and also manages a P2P group list.For example, the P2P information manager 616 broadcasts aP2P_setup_ready message by using the message generator 608. Thereafter,the P2P information manager 616 gathers information included in a P2Pneighbor report response (i.e., PNR_rsp) message processed by themessage processor 604 and stores a P2P-related message. Then, the P2Pinformation manager 616 provides P2P-related information to the modeselector 614 or the P2P setup unit 618 when necessary.

The mode selector 614 receives the P2P-related information from the P2Pinformation manager 616, selects a preferable communication mode betweenBS-assisted communication and P2P communication among the MSs, andreports the selected mode to the controller 606.

If the mode selector 614 selects the P2P communication mode, the P2Psetup unit 618 provides P2P connection information between the MSs.

In the aforementioned structure, the controller 606 is provided as aprotocol controller and controls the message processor 604, the messagegenerator 608, the mode selector 614, the P2P information manager 616,and the P2P setup unit 618. That is, the controller 606 can function asthe message processor 604, the message generator 608, the mode selector614, the P2P information manager 616, and the P2P setup unit 618.Although these elements are separately configured in the illustratedexample, this is for explanation purposes only. Thus, in practice, allor some of these elements may be controlled by the controller 606.

According to exemplary embodiments of the present invention, a BSadaptively selects a communication mode by considering a wirelessenvironment between MSs in a wireless communication system. Therefore,services can be provided in a good wireless environment. In addition,the wireless communication system can effectively use wirelessresources.

While the present invention has been shown and described with referenceto certain exemplary embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the presentinvention as defined by the appended claims and their equivalents.Therefore, the scope of the invention is defined not by the detaileddescription of the invention but by the appended claims and theirequivalents, and all differences within the scope will be construed asbeing included in the present invention.

What is claimed is:
 1. A method for operating a Base Station (BS) in a wireless communication system capable of supporting a Peer-to-Peer (P2P) communication, the method comprising: receiving a connection request message from a first mobile station (MS); transmitting a P2P setup ready message to instruct at least one MS to receive a P2P connection request message from the first MS; receiving at least one response message including an identification (ID) of the first MS from the at least one MS that has received the P2P connection request message from the first MS; determining whether to allow the P2P communication between the first MS and a second MS among the at least one MS that has received the P2P connection request message from the first MS based on the at least one response message; and transmitting a connection response message indicating whether to allow the P2P communication between the first MS and the second MS, to the first MS and the second MS.
 2. The method of claim 1, wherein the at least one response message further comprises at least one of a P2P group ID, information on channel power, and a call status.
 3. The method of claim 1, wherein the determining of whether to allow the P2P communication between the first MS and the second MS comprises: generating a list representing the at least one MS transmitting the at least one response message; and inserting information in the at least one response message into the list.
 4. The method of claim 3, wherein the list comprises information on MSs able to perform the P2P communication.
 5. The method of claim 1, wherein the determining of whether to allow the P2P communication between the first MS and the second MS comprises: if the P2P communication is possible between the first MS and the second MS, determining to allow the P2P communication between the first MS and the second MS.
 6. The method of claim 1, wherein the determining of whether to allow the P2P communication between the first MS and the second MS comprises: if the P2P communication is not possible between the first MS and the second MS, determining to allow the first MS to communicate with the second MS via the BS.
 7. The method of claim 1, wherein the request message, which is transmitted from the first MS to the second MS, comprises a message for checking possibility of the P2P communication between the first MS and the second MS.
 8. The method of claim 1, wherein the at least one response message is used for generating a list representing possibility of the P2P communication between the first MS and each the second MS.
 9. An apparatus for a Base Station (BS) in a wireless communication system capable of supporting a Peer-to-Peer (P2P) communication, the apparatus comprising: at least one processor configured to: receive a connection request message from a first mobile station (MS), transmit a P2P setup ready message to instruct at least one MS to receive a P2P connection request message from the first MS, receive at least one response message including an identifier (ID) of the first MS from the at least one MS that has received the P2P connection request message from the first MS; determine whether to allow the P2P communication between the first MS and a second MS among the at least one MS that has received the P2P connection request message from the first MS based on the at least one response message, and transmit a connection response message indicating whether to allow the P2P communication between the first MS and the second MS, to the first MS and the second MS.
 10. The apparatus of claim 9, wherein the at least one response message further comprises at least one of a P2P group ID, information on channel power, and a call status.
 11. The apparatus of claim 9, wherein the processor is further configured to generate a list representing the at least one MS transmitting the at least one response message, and inserts information in the at least one response message into the list.
 12. The apparatus of claim 11, wherein the list comprises information on MSs able to perform the P2P communication.
 13. The apparatus of claim 9, wherein the processor is further configured to, if the P2P communication is possible between the first MS and the second MS, determine to allow the P2P communication between the first MS and the second MS.
 14. The apparatus of claim 9, wherein the processor is further configured to, if the P2P communication is not possible between the first MS and the second MS, determine to allow the first MS to communicate with the second MS via the BS.
 15. The apparatus of claim 9, wherein the request message comprises a message for checking possibility of the P2P communication between the first MS and the second MS.
 16. The apparatus of claim 9, wherein the at least one response message is used for generating a list representing possibility of the P2P communication between the first MS and each the second MS. 